The present invention relates to a laundry waste water treatment and wash process and in particular to such a process using only ozone as the cleaning and disinfecting product.
Typically ozone is generated when oxygen, O.sub.2, is exposed to ultraviolet light or an electrical charge which breaks it down to individual oxygen molecules. Some of these recombine into ozone, O.sub.3. Ozone is the triatomic, allotropic form of oxygen O.sub.2. It is an unstable gas with a pungent odor and it is normally produced in low concentrations. The chemically active O.sub.3 then acts as an oxidant to break down compounds it comes in contact with.
When ozone is created by an ozonator, air is subjected to an electric discharge commonly known as a corona which is produced by an electric charge between parallel or concentric electrodes separated by a dielectric to prevent a spark discharge. Normally a blower forces air between the electrodes and when an alternating potential from 6,000-30,000 volts, depending upon the thickness of the air space and the dielectric material, is applied to the electrodes, the part of the oxygen in the air is transformed into charged oxygen atoms, ions, which conduct the electric current. Some of these ions recombine to form pre-atom molecules O.sub.3 or ozone. Because the ozone is unstable, it is important to remove the ozone as quickly as possible after it is produced and normal ozonators provide a minimum air velocity for sufficient operation to remove the ozone from the electrodes. Increasing the frequency of the power supply to the ozonator increases both the current and the yield of ozone; however, very high frequencies often require water cooling of the electrodes. Because of its instability, the ozone must be generated at the point of application and prior art systems often do not produce enough ozone for a particular application.
Since ozone is a powerful oxidant, it is well-known as a sterilizing and preserving agent as well as a chemical oxidizing agent. Among the uses for ozone are the sterilization and preservation of foods such as cheese, eggs, meat, poultry, fruit and so forth. Using ozone as a food preservation agent was known in the Republic of Germany in the early 20th century. It is also well-known in Australia to preserve meat using ozone in the mid-1930's. Ozone is well-known in the purifying and cleaning of water for a variety of purposes including drinking, bathing, cleaning and so forth.
Ozone also is used to control airborne organics, bacteria and viruses by chemically reacting with them. This makes ozone useful in health care applications as a disinfectant such as patient and operating rooms, physical therapy rooms, laundry and disposal rooms, food service industries, hotels, restaurants, livestock industries among others.
The prior art has recognized the usefulness of ozone with laundry washing processes. For example, Japanese Patent No. 2,149,293 relates to a wet clothes washing unit comprising a washing tank, a foaming device with a nozzle for dispersion of bubble generation and an ozone generator for feeding ozone containing air into the nozzle. The ozone is ejected in the form of bubbles through a porous plate which is transmitted to the wash water and laundry which helps clean the laundry without mechanical stirring to remove stains by a bleaching action. Spanish Patent No. 2,006,978 relates to an ozone generator for washing machines having an internal electrode encapsulated in the glass tube and a coaxial metal tube as an external electrode. Air is drawn by a pump over the generator electrode and passed into the wash bath. Japanese Patent No. 86-218,645 describes an electric washing machine with a built in bleaching function which incorporates an ozone generator and air diffuser pipe for blowing ozone into the washing machine to bleach clothes without using a bleaching agent. Belgian Patent No. 899,577 discloses a washing machine which agitates clothes with compressed air and ozone blown into the washing chamber. German Patent No. 3,232,057 discloses a washing machine with an ozone generator to kill bacteria using an ozone atomizer spray and feed channel which lead into the cleaning fluid vessel and acts during the rinsing phase. Another German Patent No. DE 3,007,670 describes a detergent free laundering process of textiles using an aqueous solution of bromide or bromic acid and ozone.
The present invention relates to a laundry waste water and wash treatment process wherein water is continually recycled and filtered in a washing machine system using ozone as the primary disinfecting, cleaning and bleaching agent. With this system, it is not necessary to use conventional detergents and soaps which make the water unusable except for an initial cleaning process. The process contemplates recycling the water, both during the cleaning cycle and the rinse cycle, without adverse effects to the washing process. Rather, ozone washed laundry exhibits a high quality of cleanliness and freedom from bacteria as well as providing an aesthetically clean looking and smelling laundry product.
In a preferred embodiment, water is recycled from a collection sump and is pumped to a storage tank where it is stored until it is needed for a wash cycle. When a wash cycle begins, the water is pumped from the storage tank, through a filtered line into a holding tank. The water is the holding tank is treated with ozone which is entrained into the holding tank water as it is being stored. The water in the holding tank is kept in a continual state of flow by being pumped from the tank bottom through a filter and returned to the top of the tank. When a wash cycle is activated, water is pumped directly to a washing machine or machines for use in a conventional wash cycle. After the wash cycle is complete, the water is drained into the sump and a rinse cycle is initiated by pumping additional water from the holding tank into the machines. With the present system there is no need for the water to be heated thereby enabling the fluid to be kept in a closed cycle system. Additional water is periodically added to either the storage tank or holding tank to compensate for the loss of water in the system due to evaporation, spillage and to replace the water removed by the wet laundry.
With the present system, using recycled water, water savings is considerable. When used in commercial and institutional locations, millions of gallons of water per year can be saved. The problem of eliminating waste water and the treatment of this water which in previous systems would eventually find its way back into the ecological water supply is eliminated. The ozonated wash water eliminates the use of soap and other sour and toxic chemicals and the resulting environmental degradation caused thereby. Not least of all, the present system increases the capacity of the washing machines in use, eliminates the use for hot water and generally greatly reduces the cost of laundry operations.
Among the objects of the present invention are the provision of an ozone laundry waste water treatment and wash system which saves water, eliminates the need for hot water, soap and chemicals and greatly reduces the costs of operation of the various systems.
These and other objects will become apparent with reference to the following drawings and specification.